问题嘲讽嵌套类中的DNSResolver

Question

我有以下代码：

import unittest, mock 

class MockedRRData(object): 
     def to_text(self): 
      return '0 example.com.' 


class MockedResponse(object): 
    answer = [[MockedRRData()]] 


class MockedReturnValue(object): 
    response = MockedResponse() 


class MockedDNSResolver(object): 

    def query(self, domain_name, query_type): 
     return MockedReturnValue() 


class DNSQueryTest(unittest.TestCase): 

    def setUp(self): 
#  MockedRRData = mock.Mock(to_text=lambda: '0 example.com.') 
#  MockedResponse = mock.Mock(answer=[[MockedRRData()]]) 
#  MockedReturnValue = mock.Mock() 
#  MockedReturnValue.attach_mock(MockedResponse, 'response') 
#  MockedReturnValue = mock.Mock(response=MockedResponse()) 
     self.fake_dns_resolver = mock.Mock(query=lambda *args, **kwargs: MockedReturnValue()) 

    def test_mock(self): 
     for rrset in self.fake_dns_resolver.query('a', 'b').response.answer: 
      for rrdata in rrset: 
       print(rrdata.to_text()) 

unittest.main() 

它的工作原理，但我想过渡到充分利用模拟类 - 如图所示意见。问题是，当我取消，甚至只是我的意见的最后一行，我得到如下：

E 
====================================================================== 
ERROR: test_mock (__main__.DNSQueryTest) 
---------------------------------------------------------------------- 
Traceback (most recent call last): 
    File "/tmp/a.py", line 33, in test_mock 
    for rrset in self.fake_dns_resolver.query('a', 'b').response.answer: 
TypeError: 'Mock' object is not iterable 

---------------------------------------------------------------------- 
Ran 1 test in 0.000s 

FAILED (errors=1) 

我该如何解决呢？

Answer 1

显然，我犯了一个错误，试图通过添加额外的()（mock.Mock返回一个实例，而不是类模板）两次实例化mocks。这是工作代码 - 比较以前评论的部分。

import unittest, mock 

class MockedRRData(object): 
     def to_text(self): 
      return '0 profound.mail.pairserver.com.' 


class MockedResponse(object): 
    answer = [[MockedRRData()]] 


class MockedReturnValue(object): 
    response = MockedResponse() 


class MockedDNSResolver(object): 

    def query(self, domain_name, query_type): 
     return MockedReturnValue() 


class DNSQueryTest(unittest.TestCase): 

    def setUp(self): 
     MockedRRData = mock.Mock(to_text=lambda: '0 profound.mail.pairserver.com.') 
     MockedResponse = mock.Mock(answer=[[MockedRRData]]) 
     MockedReturnValue = mock.Mock(response=MockedResponse) 
     self.fake_dns_resolver = mock.Mock(query=lambda *args, **kwargs: MockedReturnValue) 

    def test_mock(self): 
     for rrset in self.fake_dns_resolver.query('a', 'b').response.answer: 
      for rrdata in rrset: 
       print(rrdata.to_text()) 

unittest.main()